Lupo TDI not boosting (now fixed)

if the actuator hasn’t been working properly veins stick (like a wastegate sticking open) one way to tell is operate the actuator and look at the amount of movement, if it’s limited the turbo needs to come off and be stripped to free them off

 

great fun.

I was half expecting to have to replace the turbo before i even saw the car, just from the mileage alone. but, from what i've read they aren't known for eating turbo's, so hopefully it'll just be something related to the control of the boost.

I'll look into it in the morning. cheers guys

 

sounds like what my A4 tdi would do after i reset the ecu (reset due to having gone into limp).

it would work nicely for about 15 seconds, then get scared and go limp again.

once i had cured the boost leak and the stupid EGR valve, full boost returned and i was smiling once again

 

Reply from the man himself

hi the boost is fine unless you drive over 3000rpm this would piont to the variable vane in turbo sticking strip and clean usually cures it
if boost drops when driving flick ignition of then back on and boost comes back
thanks ian

will still change all the vacuum pipes anyway.

 

Quite interesting reading this. I've read a few TDI problems afterall i do own one and had problems with mine.

Heard the lower boost pipes can leak, but i've never had a leak. I just clean the EGR valve but really would love to clear the Variable Vanes as my boost can stick sometimes.

Let us know what the cure is as interested to see if i'll ever had this problem.

But my 1.4 TDI i got at 28K and its now on 45K in 15 months with no major issues.

 

Bit of progess today, changed the servo vacuum pipe as the take off on the valve was snapped off and bodged in, a reasonable 18 for the whole pipe from VAG. I also bought 5m of vaccum tube to replace the whole lot. Gave it a fresh genuine VAG diesel filter, oil filter and some genuine synta PD oil (28for 5 litres!!!).

It the first time i've really driven the car any distance, what i was finding was that it seemed to boost ok, but as soon as you coasted or tried to go over 3000rpm it'd just drop all the boost and go flat. turning the ign off and on again brought the boost back, but it still felt very flat.

So i took it up to the mk4 meet in rochdale to take part in the group buy for a remap.

Simon from http://www.ccctech.co.uk/ gave some excellent info and it was really interesting to see the remapping on progress, watching him remove the chip from 1990's car was a bit nerve racking!

Road test after the mapping was an eye opener to say the least!! revs straight round to 4.5k no problem, pulling harder than my dads 110GTTDI! pretty amaxing really for such a small engine. Smokes like the batmobile too, excellent.

But, as soon as i got on the motorway it kept cutting into the crap mode again, boost restored as soon as i turned ign on and off.

just done a run up the road with the missus watching vag com boost levels. It's meant to be between 0.65 and 1.2 bar. it barely gets over 0.5 bar, topping out at 0.75.

So I'm going to whip the turbo off and see what state it's in tomorrow.

interestingly simon reckons he knows a guy who said the pd130 turbo, injectors and manifold will fit, with the spare runner cut off and welded up. supposed to be a bit of a flying machine with that done! so that could be next on the cards.

but, the difference the remap has made is quite astounding. i actually think i could get used to this tdi lark.

 

It does sound like the vains are seized up,they run maximum boost so it goes above limit and puts in to limp mode.Switch ignition on and off resets the mode so drives as normal untill sees over boost again.
The vains can be freed off fairly easy your self but you'll have to remove the turbo.

Did you check boost actual to nominal pressure?

 

hi dan, it does figutre that the vanes are stuck yes, with the vaccum issue the solenoid that feed the actualtor just hasn't had enough vacuum to, er, actuate it! so because it hasn't been moving (and also due to the mileage) they've probably seized. will find out tomorrow.

not sure what you mean in your second paragraph? i was just looking at the manifold pressure values on vag com.

 

You can see reqested boost v actual you need to make sure there simular i've changed a lot of boost pressure sensors.

 

ah, will check that before i take the turbo off, as daz also mentioned dodgy boost sensors earlier.

 

quick little cars for what they are aint they

 

Indeed A map'd one can easily upset some larger cars.

Reading about the PD130 injectors, turbo etc... is interesting as I heard this too.

I find my boost can peak at 20psi but holds around 17psi.

It pulls all the way to 4500rpm and actually doesn't smoke that much compared to other turbo diesel engines (Also given i have a centre exhaust that throws it directly outwards)

 

Well, took the turbo off, as you can see it's pathetically small! and it also ISN'T a variable vane one at all. Just your normal common or garden turbo, nothing special.



bit oily

Note the lack of clips ont he vacuum tubing, cables ties instead....





hose had been cut off by the looks of it, then put back on with cables ties not crimped clips, and because they were now too short they didn't fit in the clips, so this has happened.


exhaust manifold. number 3 looks a bit funny



intake full of sludge



EGR sooted up to hell


broken boost pipe bracket


turbine and wastegate


spins nice and fee, but there is a tiny bit of play in the shaft. I tightened up the wastegate as it wasn't sealing very tight.

New hoses and clips


Turbo info, is it the right one?


Got it all back together, not a bad job really, a few awkward to access bolts but nothing seized up.

Had 3 runs out in it so far, no sign of any limp mode kicking in. Still sooty as hell , and boost levels are still down, and below specified pressures. MAF readings are also slightly lower than specified.

So it's still not producing full boost, but it runs well and is pretty nippy.

I'm going to do the full 70 mile run to work tomorrow and see how it behaves.

Oh, and I have to confess to actually "detailing" the car too.....but it was proper minging, and even had green mould in places.

Just to add, whoever had been trying to fix this car before is a complete and utter numpty. They'd broken the grille (leaning over the engine). left one of the bolts holding the intake pipe onto the turbo loose, snapped the connector on the MAF, broken the boost hose bracket, and not fitted the boost hose clip to the intercooler properly. And of course the aforementioned hose bodging. Rough **** numpties, created more work than they fixed. I'm a totally unqualified DIY mechanic, but can do a better job than these clowns who do it for a living, it's not even funny the mess they make.

 

Great read

How easy was it to do that? As i can see you took the turbo with the engine still in so what did you have to do?

I really want to look to if I can clean my turbo, as EGR is fairly clean and I cleaned my intercooler last month flushing the oil from inside.

Did you do it with the car jacked up and undertray removed?

 

undertray is missing....probably snapped off by the numpties.

i took it out from the top.. had to remove inlet manifold to get at 2 of the turbo bolts anyway, but then i couldn't get the turbo out so had to take off the exhaust manifold too so it'd come out.

it'd probably come out the bottom if you took the driveshaft out, but i saw no reason to disturb the driveshaft.

about 2 hours work to take off, bit less to refit.

 

Just had a look on clublupo. A lot of owners say the turbo should be a VNT style: Garrett VNT 15.

Seems you've checked the usual suspects:

MAF
N75 valve
EGR
Boost pipes
Vacum pipes
Actuator rod for movements
Air intake system

Think there was a rumour on clublupo i read that the earlier lupo TDI's had a normal style charger. With models around 2001/2 onwards being VNT.

But as you say yours is the just a normal charger type.

 

still more checks to do.

says on the label it's a GT15, the year 02 was cast into the housing.

what's VNT?

going to try removing the vacuum off the wastegate and (carefully) seeing how much boost it will actually produce. that way i can see if the turbo itself is at fault, of whether something else is limiting the amount of boost available.

 

part number checks out with ETKA too.

 

The turbo you haven't got! , ie. variable.

 

Yeah ETKA part number is correct. Will check my turbo part number tomorrow if i can get a good enough angle to view it.

Whats a VNT? Here's some reading that helped me understand more:

http://www.honeywell.com/sites/ts/tt/PassengerCars_LightTruks3_CP3HXNOKPJPUTB8SLO99Q5SFMZIHC4MW90812155218387_HBFRTGMKQK64U00ACROYP858GKIH564VY0812155701757.htm

http://www.technologie-entwicklung.de/Gasturbines/VNT15-Turbo/vnt15-turbo.html